<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!--    和c++一样-->
    <script>

        var a = 3;
        // alert(a);
        a++;
        document.write(++a+"========="+typeof(a)+"<br>")
        a="bbb"
        document.write(a+"========="+typeof(a)+"<br>")


    </script>

</head>
<body>



</body>
</html>